To provide redundancy and fault tolerance, you can specify multiple locations for a single XML document via URL groups. The syntax of a URL group is:
[URL1 | URL2 | URL2 | ... | URLn]
For example:
[file:///usr/local/default_dds.xml | file:///usr/local/alternative_default_dds.xml]
Only one of the elements in the group will be loaded by Connext DDS, starting from the left.
Brackets are not required for groups with a single URL.
The NDDS_QOS_PROFILES environment variable contains a set of URL groups separated by semicolons. For example, on Linux and Solaris systems (note: this should be entered in a single command line):
setenv NDDS_QOS_PROFILES [file:///usr/local/default_dds.xml|file:///usr/local/alternative_default_dds.xml]; [str://"<dds><qos_library name="MyQosLibrary"></qos_library></dds>"]
The url_profile field in the PROFILE QosPolicy (DDS Extension) will contain a sequence of URL groups.
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